Merhab-LGL: Monitoring and Event Response for Harmful Algal Blooms in the Lower Great Lakes

A project is being conducted as part of the MERHAB Lower Great Lakes (MERHAB-LGL) project directed by Greg Boyer at SUNY ESF to develop a transport modeling capability that can be used to predict the movement of an algal bloom in a lake. Consistent with the overall goals of the MERHAB project, models are being developed for each of the three main lakes in the study, Lakes Ontario, Erie and Champlain. The main components of this project involve coupling hydrodynamic and particle tracking models (PTM) for each of the lakes. As a first step, the Princeton Ocean Model (POM) is being used to generate circulations.  The PTM then uses the velocity and diffusivity outputs to compute movement of passively drifting tracers. Example outputs may be accessed below.   The PTM is based on a random walk algorithm that incorporates a deterministic component based on mean velocity and spatial gradients in diffusivities, and a random component formulated to produce spatial spreading statistics consistent with the diffusivities. The overall goal is to predict the transport path of a bloom once it has been identified.

The long-term objectives of the transport modeling system are to maintain a near real-time database for water velocity fields in the lakes and to provide relatively short-term predictions (over several days to several weeks) of lake circulations and transport pathways. Simulations need to be developed with a short turn-around time, in order to be useful as part of the monitoring project, and current efforts are directed at accessing the university's supercomputer for this purpose.